Franca - I'd second anything with a Seagate drive in it; Toshiba drives are also good. Maxtor and Lacie have poor reputations for reliability, and anything unbranded is probably not worth risking your data for. (Based on many years experience of hubby building a fair number of PCS and having to replace failed drives, or not in the case of Seagate.) Of course, all this is statistical, so you may get the occasional dud in any make.

My daughter had one such and it failed after a few weeks, but both kids are now set up with 500Mb Seagate drives that have worked for a year (I shouldn't tempt providence with that, should I?)